Focus Adjustment - Memorex MT1190C Service Manual

GREEN
RED BLUE
RED
GREEN
BLUE
(A)
GREEN
BLUE RED
BLUE
GREEN
RED
(B)

FOCUS ADJUSTMENT

Adjust focus control, located on the Horizontal Output Transformer (T671), for maximum overall definition and fine
picture detail with Brightness and Contrast controls set at normal viewing levels.
BLACK AND WHITE ADJUSTMENT (CUTOFF / WHITE BALANCE)
The purpose of this procedure is to adjust the bias applied to the color picture tube for reproducing a quality
monochrome picture at all brightness levels and also to achieve maximum usable brightness. Confirm that proper
purity and AGC adjustments have been completed before starting this adjustment.
1. Connect the TV test pattern generator (Monoscope pattern) to the EXT. antenna terminal via TV VHF/UHF
signal generator (NTSC signal, 70dB u).
2. Select Cutoff Mode by remote control, (refer to page 4 for remote control key combination and position) and
CUT OFF will be displayed on top-right screen for about 3 seconds. At the same time the data readings for
Cutoff and Gain in Adjustment Mode (2) will become as follows:
R CUTOFF: 50, G CUTOFF: 50, B CUTOFF: 50, G GAIN: 127, B GAIN: 127
3. Select Service Mode by remote control, (refer to page 4 for remote control key combination and position) and
TV screen becomes horizontal line.
4. Turn the Screen control (located under the flyback transformer) clockwise until any blue, green or red color
line appears.
5. Check the color of the line which appeared first, then turn the Screen control (located under the flyback
transformer) fully counterclockwise.
6. Adjust the cutoff level of the color which appeared first by remote control, (refer to page 4 for remote control
key combination and position) so that voltage between TP16 and TP15 (blue), TP14 (green) or TP13 (red) is
20 ± 1V.
7. Turn the Screen control (located under the flyback transformer) clockwise so that the bright color line can just
be seen.
8. Adjust cutoff levels other than the above by remote control, (refer to page 4 for remote control key combination
and position) so that the line color is white.
9. Press again Service Mode key by remote control, (refer to page 4 for remote control key combination and
position) to return to TV position. Monoscope pattern will appear on TV screen.
10. Adjust the contrast and brightness controls to make the picture dim. Adjust the Green and Blue Cutoff levels
by remote control, (refer to page 4 for remote control key combination and position) so that the picture is white.
11. Adjust the contrast and brightness controls to make the picture bright. Adjust the Green and Blue Gain levels
by remote control, (refer to page 4 for remote control key combination and position) so that the picture is white.
12. Repeat steps 10 and 11 so that the picture is white in both dim and bright conditions.
WEDGE A
DEFLECTION YOKE REAR VIEW
WEDGE B
DEFLECTION YOKE REAR VIEW
Fig. 5
GREEN
BLUE RED
RED
GREEN
BLUE
BLUE
GREEN
RED
RED BLUE
GREEN (C)
GREEN
RED BLUE
BLUE
GREEN
RED
RED
GREEN
BLUE
BLUE RED
GREEN
(D)
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WEDGE B
WEDGE C
WEDGE A
DEFLECTION YOKE REAR VIEW
WEDGE B
WEDGE C
WEDGE A
DEFLECTION YOKE REAR VIEW